Many interrupt transactions to low/full speed devices are getting QTD_STS_MMF from the EHCI controller because the split transaction isn't completed in time. This happens when the EHCI controller tries to read main memory during a CPU frequency change, and it can't get the data back in time, presumably due to the processor not being able to complete a cache snoop in a timely manner when changing frequency.
This results in ehci_hcd returning -EPROTO to drivers like hid-core, and results in lost keystrokes, as well as messages like "usb 3-3.1: reset low speed USB device using ehci_hcd and address 7". This could presumably also affect non-HID devices. This patch turns off periodic list processing in the EHCI controller for the duration of processor frequency changes. Signed-off-by: Stuart Hayes <[EMAIL PROTECTED]>
ehci_cpufreq_2.patch
Description: ehci_cpufreq_2.patch
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